For engines built before 1996, these catalytic converters have stainless steel ribbed bodies that minimize expansion/distortion when the converter heats up. The ribs form a channel that protects pads from direct exposure to exhaust gas, plus they keep the ceramic catalyst aligned. Rigid OE-type heat shields add structural stability, and strong 1/2" lap-joints fuse necks to the body (for best flow, necks don't extend into bodies). Made in the USA.

3. If the engine has been changed and is not the same model year as the chassis, proceed as follows:

For engines older than the chassis, select the converter based on the chassis model year.

For engines newer than the chassis, select the converter according to the engine requirement.
4. It is necessary to know which type of catalytic converter was originally used on the vehicle: 2-Way, 3-Way, or 3-Way + Air. Required by the EPA, this information (abbreviations listed below) is on the vehicle emission control label in the engine compartment. The label should be visible on the firewall, hood's underside, radiator support, fan shroud, or shock tower.

2-Way (Oxidation) = OC or COC

3-Way (Oxidation Reduction) = TWC or ORC

3-Way + Air (3-Way plus Oxidation) = TWC/OC or ORC/OC

Note: 49-State Catalytic Converters are not legal for sale, installation, or use on licensed vehicles in the state of California.